1. Field of the Invention
The present invention is directed to a fault information collection processing system in a program-stored communication control processing module for controlling data communication between a central processing unit and data communication lines on the basis of appropriate communication control programs.
2. Description of the Prior Art
One typical arrangement of a large scale electronic computer network in the field of sophisticated electronic computer systems involves intricate combinations of a plurality of central processing units and a multiplicity of data communication lines with decentralized processing pervading. In this type of electronic computer network, it is a widespread practice for the communication control processing module, which stores an appropriate communication control program and functions independently of the central processing unit, to be connected to an input/output channel so that there is no drop in the processing capability of the central processing unit in controlling the data communication lines, which requires a variety of transmission control procedures.
FIG. 1 illustrates a block diagram showing the configuration of an example of this type of electronic computer network. In FIG. 1, the symbols 1a through 1c designate a plurality of central processing units for performing the arithmetic and control operations required for data processing. Communication control processing units respectively indicated at 2a, 2b and 2c are connected to central processing unit 1a, 1b and 1c. The symbols 3a to 3c represent input/output channels through which central processing units 1a to 1c are connected to communication control processing units 2a through 2c. Data communication lines 2a, 2b and 2c serve to connect communication control processing units 2a through 2c to each other. Terminal units 5a, 5b and 5c are connected via terminal data communication lines 6a, 6b and 6c to communication control processing units 2a through 2c.
FIG. 2 is a block diagram depicting the internal configuration of each of the communication control units 2a to 2c depicted in FIG. 1. Referring to FIG. 2, reference numeral 2 denotes a communication control module, and 3 designates an input/output channel for connecting central processing unit 1 to communication control unit 2. Communication control module 2 functions to control input/output channel 3 so as to cause them to transfer the data between central processing unit 1 and the module 2 itself. To be more specific, communication control module 2 is composed of: a channel control unit 7 for controlling data transfer between input/output channel 3 and communication control processing module 2; a storage unit 8 for storing a communication control program 9 and the data transferred to data communication lines 4 and 6; a line control unit 11 for controlling the data transfer between data communication lines 4 and 6; and a central control unit 10 which executes communication control program 9 for the purpose of controlling channel control unit 7, storage unit 8 and line control unit 11.
We will next deal with the function of the program-stored communication control processing module. In the case of effecting data communication by use of the electronic computer defined as a destination station for the communication, the program of the central processing unit 1 depicted in FIG. 2 involves the preparation of a piece of destination information for the communication as well as a communication statement, and the data are thereby transferred and received by way of input/output channel 3 between communication control processing module 2 and central processing unit 1. The particular processing associated with the subsequent data communication is executed on the basis of communication control program 9 in communication control processing module 2. Such processing is, as a matter of fact, executed by central control unit 10 which sequentially reads commands from communication control program 9 stored in storage unit 8.
On the occasion of a data transmission from central processing unit 1 to data communication lines 4 and 6, the communication destination address and communication statement transmitted via input/output channel 3 are temporarily loaded through channel control unit 7 into storage unit 8 under the control of central control 10. Subsequently, the communication destination address is decrypted under the control of communication control program 9, and the communication statement to which transmission control characters pursuant to individual communication rules are added is transferred to line control unit 11 in transmission control procedures that are preset in the communication statement for each communication line. After a parallel/series conversion of data has been effected in line control unit 11, the data on the communication statement including the transmission control characters are sent to data communication lines 4 and 6.
In the receipt of data by central processing unit 1 from data communication lines 4 and 6, data containing the transmission control characters transmitted from data communication lines 4 and 6 undergo series/parallel conversion in line control 11. The thus converted data are then organized into a communication statement and destination information by deleting the transmission control characters under the control of communication control program 9, thereby loading such statement and information into storage unit 8. Thereafter, central control unit 10 transmits to the central processing unit 1 only the communication statement and destination information via channel control unit 7 and via input/output channel 3. It follows that, by virtue of the role played by communication control processing module 2, the central processing unit 1 is set free from such processes as identification of complicated transfer destinations and addition or deletion of control characters pursuant to the respective communication rules.
The prior art communication control processing module is, however, arranged such that the individual component devices are, as illustrated in FIG. 2, radially disposed about central control unit 10 on which the control functions of decrypting and executing communication control program 9 are concentrated. Hence, in a conventional fault information collection processing system in which certain faults occur in components of the hardware, central control unit 10 itself has to control the collection of pieces of information on each fault that occurs. It is therefore difficult to collect detailed information. On the other hand, before transferring the fault information to central processing unit 1, channel control unit 7 organizes the fault information gathered by central control unit 10 into information of several bytes. The thus organized information of several bytes is merely transferred as a hardware function of channel control unit 7 to central processing unit 1 in the form of channel-state information concomitant to the input/output operations associated with central processing unit 1. The fault information is inadequate in terms of both quality and quantity.
Speaking of the various sorts of computer systems which have been proposed of late, construction of a complicated electronic computer network involves a step of combining, as depicted in FIG. 1, a plurality of central processing units 1a, 1b and 1c with a plurality of communication control processing units 2a, 2b and 2c, respectively. The number of component devices inclusive of other input/output devices becomes extremely high and this leads to the fact that the component devices experience many kinds of faults. If rectification is based on the conventional fault information collection processing system, it is difficult to pin-point the trouble spots and to reduce the time required for restoration of normal conditions. To copy with the foregoing problems, there has been an increasing demand in recent years for a method of facilitating maintenance based on bringing together in central processing units 1a through 1c pieces of fault information relative to individual devices that combine to form a computer system and systemmatically arranging such information into easy-to-observe system fault information for use by maintenance staff. The conventional fault information collection processing system involves certain inherent problems, however, since the information transferred from communication control processing modules 2a, 2b and 2c to central processing units 1a, 1b and 1c is insufficient, and it is impossible to create accurate system fault information in central processing units 1a through 1c. Thus the above-described need has not been satisfactorily met.